Inet4AddressImpl still uses the APIs gethostbyname and gethostbyaddr whereas the Unix Inet4AddressImpl and the Inet6AddressImpl variants on both Unix and Windows already use the more modern APIs getaddrinfo/getnameinfo.

As per the Microsoft documentation, gethostbyname and gethostbyaddr are considered deprecated (cf. https://msdn.microsoft.com/en-us/library/windows/desktop/ms738524(v=vs.85).aspx )